Trophic and environmental drivers of the Sechura Bay Ecosystem (Peru) over an ENSO cycle

摘要: Interannual environmental variability in Peru is dominated by the El Nino Southern Oscillation (ENSO). The most dramatic changes are associated with warm (EN) phase (opposite cold La Nina phase), which disrupts normal coastal upwelling and affects dynamics of many marine terrestrial resources. This study presents a trophic model for Sechura Bay, located at northern extension Peruvian system, where ENSO-induced extreme. Using an initial steady-state year 1996, we explore ecosystem through 2003 (including strong EN 1997/98 weaker 2002/03). Based on support from literature, force biomass several non-trophically-mediated ‘drivers’ (e.g. Scallops, Benthic detritivores, Octopus, Littoral fish) to observe whether fit between historical simulated (by model) improved. results indicate that Bay Ecosystem relatively inefficient system community energetics point view, likely due periodic perturbations ENSO. A combination high productivity low level target species invertebrates (i.e. scallops) fish anchoveta) catches efficient fishery. importance drivers suggested, given small improvements simulation addition remaining functional groups’ dynamics. An additional multivariate regression presented scallop Argopecten purpuratus, demonstrates significant correlation both spawning stock size riverine discharge-mediated mortality catch levels. These discussed context appropriateness trophodynamic modeling open systems, how management strategies may be focused highly environmentally influenced resources region.